The present invention is directed to a multiple-opening sleeve valve of a type which can be used for flow control and pressure dissipation and in particular to a multiple opening sleeve valve having a reduced length, compared to at least some previous configurations.
Multiple-orifice sleeve valves are used in a number of applications including flow control and pressure dissipation applications, such as applications requiring reducing a high inlet pressure to a lower maximum output pressure through a relatively wide range of flows. For example, multiple-orifice sleeve valves can be used for receiving flow in the range of 0 to 250 cubic feet per second (cfs) at a pressure of about 85 pounds per square inch (psi) or more, and outputting at a pressure maximum of 12 psi and the like. A description of one type of multiple opening sleeve valve can be found, e.g., in U.S. Pat. No. 4,508,138 issued Apr. 2, 1985, incorporated herein by reference. Some types of sleeve valves have been configured to provide desired performance while reducing cavitation, noise, wear and/or vibration leading to long service life, including, e.g. providing tapered sleeve openings and/or cavitation control. Examples include at least some devices sold under the trade name POLYJET(copyright), available from CMB Industries, Fresno, Calif.
Although multiple opening sleeve valves have proved useful and successful in numerous applications, it is believed there are still opportunities for providing new configurations, e.g. to assist in meeting certain needs or providing certain conveniences. At least some previous configurations of multiple-opening sleeve valves have included movable gates (or rings) and/or actuators therefor, which have led to devices which occupy a certain amount of length. The length constraints in such previous devices may lead not only to limitations on the location in which the valve can be placed, but also direct and indirect cost effects, including the size and configuration of buildings or other enclosures for the valve, the types of existing systems into which it is feasible to retrofit the valves, the weight (and thus manufacturing, storage and transportation costs) for the valve and the like. Accordingly, it would be useful to provide a multiple-orifice sleeve valve which can be provided in a reduced-length configuration (compared to at least certain previous valves) and/or which can be fabricated, shipped, installed or enclosed at reduced costs (compared to previous valves).
Some previous valves provided for linear movement using a linkage or levering mechanism, such as a yoke mechanism. Typically in such designs, the source of the force for achieving movement (such as a motor or the like) outputs force in a direction other than parallel to the gate movement (during at least a portion of the stroke). Such configurations have certain disadvantages including loss of inefficiency and thus lower effective operating forces for a given motor output, and/or limited range of effective stroke length (and thus limited range of gate movement). Accordingly, it would be useful to provide a reduced-length multiple orifice sleeve valve which can avoid at least some efficiency losses and/or stroke length limitations, e.g., compared to non-in-line and/or yoke configurations.
In many previous approaches, substantially all of the actuation mechanism was configured so as not to be internal to the valve. Although these approaches were useful in some regards, such as avoiding the potential for actuator lubricants to contaminate the water or other fluid, substantially-external configurations have created certain pressure imbalances and/or drag associated with seals or packing, leading to high effective operating (gate opening or closing) torque. Accordingly, it would be useful to provide a multiple orifice sleeve valve in which it is feasible to provide some or substantially all of the actuator or actuator linkage in an internal mounting to the valve or otherwise facilitating a reduction in the operating torque.
In many previous approaches, wearing components associated with gate movement had been relatively large and/or inaccessible, often requiring extensive disassembly, and associated valve down-time, for replacing components as wear occurs. Accordingly, it would be useful to provide a multiple orifice sleeve valve with improved ease of access to, and/or replacement of, at least certain wear components, e.g., for reducing maintenance down time and/or maintenance costs.
The present invention includes the recognition of the existence, source and/or nature of problems in previous approaches including as described herein. In one aspect, the present invention provides for moving the gate by rotating a threaded rod which engages a nut or other threaded hole, substantially fixedly coupled with respect to the gate. Preferably, the threaded rod is engaged at a position, along the gate, which is spaced from the upstream-most edge of the gate and, preferably, substantially adjacent the downstream-most edge of the gate. In one aspect, the threaded rod and/or nut are formed from materials which do not require external lubrication (i.e. lubrication other than whatever lubricating qualities may be provided by the fluid normally flowing through the valve), such as using stainless steel and/or brass. In the absence of external lubricants, it becomes feasible to provide the threaded rod/nut configuration such that the threaded rod may normally be in contact with the water (or other fluid flowing through the valve), e.g. without the need for providing a sealed drive tube. Using a threaded nut or similar configuration, rather than a drive tube, reduces the total length of the drive structure required, permitting the sleeve valve to have a length which is shorter than, e.g., drive tube configurations, such as being shorter by an amount about equal to the sleeve diameter (or more). In this way, a multiple-opening sleeve valve can be provided with a reduced length while providing a gate actuator/drive system which is substantially in-line (i.e., providing force substantially parallel to the direction of gate movement substantially throughout the stroke) thus avoiding deficiencies associated with yoke drives or similar approaches (such as power inefficiencies and/or relatively short effective stroke lengths).
In one aspect, a multiple opening sleeve valve is provided with a gate movable to control flow or pressure without the need for axial movement of a component through a pressure-containing seal. A gate actuator can include a drive rod and nut coupled to a gate substantially internal to the valve housing without the need for grease or similar external lubrication. The valve can provide for relatively high in-line gate-moving force, a reduction in force or torque requirements for operation, increased ease of wear-part replacement and decreased overall valve length, compared to previous valve configurations of comparable size or capacity.